Not sure what flooring needed to site Rangemaster

Wooden flooring is known for its elegant look. It creates a warm ambience inside your home. Hardwood floors are elements of d?cor themselves, which are available in many different types and colours. Its durability will ensure a good interior investment while providing aesthetics to your home.

If by “building a wooden floor “you mean putting down hardwood flooring, my biggest advice is to invest in a $50 laser measure from Lowe’s home improvement. There are just too many mistakes that you can make with a tape.
Also look up on the web about making a spline, in order to reverse the direction of the tongue & groove of the flooring. I cost myself a lot of time and money not knowing about those.

nothing wrong with engineering.
its down to your budget

Assuming that you've installed the stack kit according to instructions, you should check the following:
1. The dryer should be securely attached to the washer and not wiggle or move. The washer must always go on the bottom of the stack.
2. Washer should be level and have all four level legs making solid contact with the floor, no wobbling.
3. Make sure the drain hose is not pinched or restricted (or there is not debris in the drain pump) as a slow pump out will accentuate vibration problems.
4. Make certain you've removed all of the washer packing bolts before using the machine (see owners manual for description.)
5. The floor must be solid with no "springy" or "spongy" feel. No matter what you do to the laundry set it will vibrate on a less than solid floor. This occurs on upstairs installations or other wooden floors, especially in an older home. Sometime the floor can be braced to stiffen it. Also, vibration pads are sold that might help minimize the vibration. The walking is a symptom of vibration.

Experience shows that most problems of this sort result from incorrect installation and/or flooring issues, not the laundry. You should not attach it to the wall. It is possible the washer has a problem in which case a technician would need to check the unit. They can check the suspension and drive system for proper operation.

A friend of mine built an 18 inch high wooden base to raise his wife's washer & dryer because of her bad back, and he had no trouble with it. Speaking as a carpenter, I would make sure that your base is designed strong enough to hold the weight of both machines plus the water that will be in the washer. Use 3/4 inch plywood for the top of the base, with a 2x4 frame underneath. If it will be sitting directly on a cement floor, use treated lumber to avoid wood rot.

these machines can have this problem when placed on a pedestal and/or the floor may be level but not solid. a "bouncy" floor will amplify any movements. remember, these machines are much heavier and spin much faster than top-loaders. just because it doesn't jiggle doesn't mean the floor is level. you may have to brace to floor or foundation somehow

Nothing is wrong w/ the unit. It must be solid on the floor with no movement in the feet relative to the flooring or it will rock when spinning. Floor is simply not solid enough. Use slower spin speed to alleviate issue or relocate it. Thanks, please leave feedback or contact me again for more info if you need it.

Try placing it on a rubber mat or carpet that has a rubber backing. The floor may be too smooth and allows it to walk.